Dice mechanics
Percentile (d100) checks in Call of Cthulhu 7th Edition
Roll under skill mechanics and difficulty bands.
Explanation
Call of Cthulhu uses percentile skills: roll d100 and succeed if you roll at or under your skill. Difficulty often shifts the threshold (Regular/Hard/Extreme) and Sanity loss is a core pressure loop.
At the table (quick loop)
- Pick the relevant skill (e.g., Spot Hidden, Library Use).
- Roll d100 and compare to your skill rating (and difficulty threshold).
- Apply consequences: information gained, complications, or Sanity loss when appropriate.
Example: Spot Hidden 55%: a roll of 42 succeeds; a harder threshold would require a lower roll.
Examples
Example: skill target
Spot Hidden 55%: roll 55 or under to succeed. Hard = 27 or under. Extreme = 11 or under.
Example: fail forward
If the clue matters, don't block progress on failure. Trade success for time, noise, or a new complication.
Common mistakes (smallest fix)
- Mistake: Forgetting difficulty bands. Fix: Use Regular/Hard/Extreme (or your table’s bands) to express stakes quickly.
- Mistake: Failure stops the investigation. Fix: Fail forward: you still get something, but pay a cost.
Call of Cthulhu 7th Edition FAQ
How does the percentile system work in Call of Cthulhu?
How does the skill improvement system work?
What are the Characteristics in Call of Cthulhu 7e?
How does Sanity work in Call of Cthulhu?
What are Occupations in Call of Cthulhu?